PDA

View Full Version : Article on Taricha granulosa


TJ
16th February 2005, 03:55
The deceptively cute newt: 'You don't want to kiss them'

By Lynda V. Mapes

Seattle Times staff reporter

It's hard to imagine this sweet-looking creature with the face of E.T. is 10,000 times more toxic than a slug of cyanide, but so it is.

The orange-bellied, rough-skinned newt is one of the most poisonous creatures going. The merest bite creates a severe burning sensation in the mouth.

Every known mammal spits them out instantly Eexcept men in bars who have been drinking heavily. A 29-year-old from Oregon went into a bar July 9, 1979, and, on a bet, swallowed a rough-skinned newt. He was dead before the day was out.

No known antidote exists for a newt's poison, packed by both juveniles and adults in glands in their skin, and even their eggs.

The poison is tetrodotoxin, or TTX, and is found in Japanese puffer fish and some species of South American frogs.

Taricha granulosa, not surprisingly, have no predators, but the common garter snake is immune to their poison. The newt's deadliest foe is the automobile.

Newts are slaughtered every spring as they cross roads to head to their breeding ponds. Habitat destruction is also doing them in. Washington's amphibians are actually in greater peril than those in any state except California, Oregon and Nevada. Here, 32 percent of the state's amphibian species are at risk, a recent Nature Conservancy study found.

Rough-skinned-newt populations are an exception, so far. They are among the five most-common amphibians in Washington, and also one of the easiest to find and identify.

Up to 8 inches long, and lizardlike in appearance, newts could pass for baby dinosaurs with their rugged, grainy skin, and brontosauruslike body.

They are the only salamander that is active above ground, out in the open and during the day Eand slow-footed to boot. Why not, when you are poison-packed?

Rough-skinned newts belie their name at breeding time, when the brown, granular skin of the male becomes smooth and supple. The tail also changes shape, becoming more flat and paddlelike for swimming.

The sight of newts on the move to the breeding ponds is one of the earliest signs of spring. The mating season, already under way, kicks off well before Valentine's Day and extends through April.

Newts are site-faithful, always returning to the same breeding pond.

Their homing instinct is remarkable: In one experiment, every newt transported in a light-tight bucket more than a mile from their home pond found the way back within a year, said Bill Leonard, an endangered-species biologist for the National Marine Fisheries Service.

Once at the pond, males patrol the shore for females. So hair-trigger ready are they for breeding that if a stick is tossed in their path, the males will approach it to see if it is a mate, said Robert Storm, professor emeritus at Oregon State University.

A single female approaching the breeding pond can be swarmed by dozens of males, creating a wiggling wad of newts big as a softball.

Courtship is an elaborate and lengthy affair.

The male grasps the female behind her front legs and crawls on her back, locking onto her and holding her tight for hours, underwater, where the two breathe through their skin.

Afterward, the male walks in front of his mate Eunderwater. As he walks along in the shallows, she follows closely, picking up jellied packets he has left topped with a dollop of sperm.

She stores the sperm inside her reproductive tract until she lays her eggs. The fertilized eggs are deposited one at a time on subaquatic vegetation.

Larvae hatch out within about a month, depending on water temperature. They emerge equipped with tiny, feathered external gills, giving them a space-alien appearance. The newts spend the spring and summer swimming about and chowing down on larvae and other tiny fare.

By August, their feathered gills have been re-absorbed to tiny nubbins and the newts have grown lungs and nostrils. They head to the uplands and the forest with the coming of the autumn rains.

Rough-skinned newts hunt their food, walking the forest floor and wagging their heads from side to side in search of snails, small slugs, insects and other invertebrates, which they bag with their sticky tongues.

Living three to 10 years, newts can be found in surprising density: Leonard remembers collecting 500 newts in one trap on one night at Fort Lewis.

Kelly McAllister, a biologist with the Washington Department of Fish and Wildlife, has been monitoring a pond south of Olympia for nearly 10 years. He has never come back without seeing some newts.

Virginia rails and blackbirds that share the boggy realm of the newt don't even come near as the newts swagger about on land, with their all-terrain, hand over hand, four-wheel amphibian drive. Eat one, and those birds would be dead in 10 minutes.

Scientists have exhaustively examined the newt's astounding toxicity, learning by force-feeding macerated newt skin to various animals that a single newt contains enough neurotoxin to keel over 1,500 white mice.

Scientists have tested 30 potential predators of newts, from belted kingfishers to great blue herons to bullfrogs and fish, finding in every case that the newt killed them.

Sometimes the newt crawled unharmed out of the gasping mouth of the deceased within minutes of being swallowed.

A sample of the poison had lost none of its potency when examined 11 months after storage.

Rough-skinned newts are common from the Coast Range near San Francisco through the entire west side of Washington all the way to Southeast Alaska. They are found as far east in Washington as Klickitat County. They are one of the most common amphibians in Western Washington, along with Pacific tree frogs, red-legged frogs and long-toed salamanders.

Handling them is a treat: They have soft, smooth skin, sweet faces and delicate, grasping arms and toes. It's OK to pick them up, but don't mistakenly brush your fingers to your lips or mouth until you wash your hands thoroughly.

Light as a ballpoint pen, a newt will rest in the palm, climbing with its forearms up to the index finger to have a look around. Look it in the eye, and the newt stares right back with a wise expression, not seeming a bit worried. Placed back on the ground, it walks off sedately, with a one-bite-and-you're-dead strut.

If startled, newts will sometimes display a so-called unken reflex: They shut their eyes and arch their back and tail upward to display a cantaloupe-orange belly. It's a warning to a potential predator of the newt's toxicity: The combination of a dark-brown, almost-black back and orange belly is a well-known Mr. Yuk sign in nature.

For all their toxicity, their appeal is undeniable.

"They are one of my favorites," said Lynn Havsall, former director of the Camp Long Nature Center in Seattle. "So beautiful. You just don't want to kiss them."

Source: The Seattle Times, February 24, 2003

pamela
21st February 2005, 04:57
Hi Tim, neat article. It's fun, for me especially, since I live in the Seattle area. I still haven't seen any migrating to ponds yet. They probably wait, and spy me, 'til I give up and go home - then come out. Oh well.

pin-pin
22nd February 2005, 18:49
http://www.caudata.org/forum/clipart/love.gif

Nice Tim. Taricha power!

pamela
18th March 2005, 17:25
Well, the Tarichas have finally come out. About an hour after sunset, I decided to check out my pond. Sure enough, in about 12" of water off shoreline, about every 3 - 5' apart, were male Tarichas - just waiting for their girlfriends to show up. I did see two females, very fat, and lethargic, laying in the shallows. It is a wonderful experience. Now for the rest of the girls...

TJ
18th March 2005, 23:42
Pictures, Pamela, pictures! http://www.caudata.org/forum/clipart/biggrin.gif